1. Field of the Invention
This invention relates to temporary roadways, and more particularly to reusable wooden mat units which can be easily transported and interlocked with other to form a strong wooden roadway for undeveloped areas.
2. Brief Description of the Prior Art
Wooden mats are known in the art for use in highway and construction sites. There are several patents which disclose various wooden mat constructions.
Brown, U.S. Pat. No. 70,514 discloses a wood pavement construction formed of embedded foundation timers in an arch shape from curb to curb which support plurality of interlocking wooden blocks.
McCauley, U.S. Pat. No. 152,299 discloses a wood pavement formed of a series of spaced apart lateral and longitudinal stringers with sand fill packed between and which support a plurality of wooden pavement blocks.
Smith, U.S. Pat. No. 2,652,753 discloses an intermeshing matting comprising parallel upper and lower runners connected to a series of parallel transverse members disposed therebetween. The ends of each adjacent pair of upper runners are staggered to terminate intermediate the width of the end transverse member or terminate beyond the end transverse member. The ends of each adjacent pair of lower runners is staggered opposite to the runners above them. Modifications include a pattern of staggering every other runner, or a single runner and an adjacent pair. There is no provision for interlocking the units in a side by side arrangement, and the disclosure suggests that in most case it is not necessary to positively connect the sections together, as the friction of interfitting is allegedly sufficient for this purpose.
Leyendecker U.S. Pat. No. 2,819,026 discloses two-ply wooden mats which interlock only in end-to-end relation.
Davis, et al, U.S. Pat. No. 4,289,420 discloses a wooden mat comprising a surface layer of longitudinal top wooden planks, an intermediate layer of transverse planks more widely spaced, and an underlying layer of longitudinal bottom planks. A short stabilizing plank is mounted transversely at the end of the longitudinal bottom planks. The ends of the top layer are alternately staggered in a manner to provide alternate longitudinally staggered lap joints for interconnecting the ends of a like mat. The ends of the intermediate transverse planks extend outward the same distance on one side, such that the rotating one mat through 180 degrees and interlocking the extended ends, the sections may be interlocked side by side. To disassemble such an interlocking system once connected, it becomes necessary to dismantle almost one entire section to remove one section from another.
Penland U.S. Pat. No. 4,462,712 discloses an interlocking mat assembly comprising a plurality of assemblies of two-ply laminated mats which interlock and are secured together by nailing a top layer of planks over the interlocked mats. This mat assembly has the disadvantage of higher labor costs in assembly and disassembly.
Waller U.S. Pat. No. 4,600,336 discloses a wooden mat assembly of three-ply construction designed to interlock along the top and intermediate layers along the ends and edges. The orientation of the planks and mode of interlocking is primarily for platforms rather than roadways and no provision is made for spaced tracks for vehicles on the top layer when used as a roadway.
The prior art in general, and none of these patents in particular, disclose a reusable interlocking wooden mat assembly having lifting and transporting means and novel interlocking construction with spaced tracks for vehicles when assembled as a roadway.